In building constructions with a steel framework made up essentially of upright and horizontally disposed I-beams, various types of crane operated lift hooks that have been employed for lifting and positioning the beam so as to span a pair of upright beams and for supporting the beam until it has been interlocked therewith as by bolts or welding.
The difficulty heretofore has been the lack of an effective mechanism which will clamp the I-beam top flange adjacent its opposite ends and which will provide a support adapted to receive a pair of hooks at the ends of chains or cables extending from a lift crane.
One important problem is the effective anchoring of the respective ends of the beam by a suitable clamping means such that the beam can be lifted and normally supported in a horizontal position until it is properly located and secured into position between a pair of right angularly related beams.
There is always the inherent danger in the use of make shift devices for mounting over the ends of the beam, the possibility that these devices may disengage from the beam end and possibly cause a serious accident.